IPAC2022 - List of Keywords (RF-structure)

Paper	Title	Other Keywords	Page
MOPOST022	Upgrade of the Radio Frequency Quadrupole of the ReAccelerator at NSCL/FRIB	rfq, operation, vacuum, MMI	104
	A.S. Plastun, J. Brandon, A.I. Henriques, S.H. Kim, D.G. Morris, S. Nash, P.N. Ostroumov, A.C.C. Villari, Q. Zhao, S. Zhao FRIB, East Lansing, Michigan, USA D.B. Crisp, D.P. Sanderson NSCL, East Lansing, Michigan, USA
	Funding: Work supported by the National Science Foundation under grant PHY15-65546 The ReA-RFQ is a four-rod room-temperature structure aimed to be the first step acceleration of rare isotopes as well as stable beams before injection into the ReA SRF linac. The beams of charge to mass ratios of 1/5 to 1/2 from the Electron Beam Ion Trap at 12 keV/u should be accelerated to at least 500 keV/u to be efficiently accelerated in the main SRF linac. Since the commissioning of the original ReA RFQ in 2010 the design voltage has never been reached, and CW operation was never achieved due to cooling issues. In 2016 a new design including trapezoidal modulation was proposed, which permitted achieving increased reliability, and would allow reaching the original required specifications. The proposed new rods were built and installed in 2019 and commissioned in the same year. Since then, the RFQ has been working very successfully. Recently it was opened for inspection and verification of its internal status. No damage and discoloration were observed. This contribution will describe the RFQ rebuild process, involving specific RF protections and other technical aspects related to the assembly of the structure. Results of the operation with a variety of beams will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST022
About •	Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 11 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOST020	Visualisation of Pareto Optimal Spaces and Optimisation Solution Selection Using Parallel Coordinate Plots	cavity, impedance, GUI, ECR	2487
	S.J. Smith, R. Apsimon, G. Burt, M.J.W. Southerby Cockcroft Institute, Lancaster University, Lancaster, United Kingdom S. Setiniyaz Cockcroft Institute, Warrington, Cheshire, United Kingdom S. Setiniyaz Lancaster University, Lancaster, United Kingdom
	In this paper, we build on previous work where multi-objective genetic algorithms were used to optimise RF cavities using non-uniform rational basis splines (NURBS) to improve the cavity geometries and reduce peak fields. These optimisations can produce thousands of Pareto optimal solutions, from which a final cavity solution must be selected based on design criteria, such as accelerating gradient and power requirements. As all points are considered equally optimal, this can prove difficult without further analysis. Here we focus on the visualisation of the Pareto optimal points and the final solution selection process. We have found that the use of clustering algorithms and parallel coordinate plots (PCPs) provide the best way to represent the data and perform the necessary trade-offs between the peak fields and shunt impedance required to pick a final design.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST020
About •	Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 29 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Other Keywords

Page

MOPOST022

Upgrade of the Radio Frequency Quadrupole of the ReAccelerator at NSCL/FRIB

rfq, operation, vacuum, MMI

104

A.S. Plastun, J. Brandon, A.I. Henriques, S.H. Kim, D.G. Morris, S. Nash, P.N. Ostroumov, A.C.C. Villari, Q. Zhao, S. Zhao
FRIB, East Lansing, Michigan, USA
D.B. Crisp, D.P. Sanderson
NSCL, East Lansing, Michigan, USA

Funding: Work supported by the National Science Foundation under grant PHY15-65546
The ReA-RFQ is a four-rod room-temperature structure aimed to be the first step acceleration of rare isotopes as well as stable beams before injection into the ReA SRF linac. The beams of charge to mass ratios of 1/5 to 1/2 from the Electron Beam Ion Trap at 12 keV/u should be accelerated to at least 500 keV/u to be efficiently accelerated in the main SRF linac. Since the commissioning of the original ReA RFQ in 2010 the design voltage has never been reached, and CW operation was never achieved due to cooling issues. In 2016 a new design including trapezoidal modulation was proposed, which permitted achieving increased reliability, and would allow reaching the original required specifications. The proposed new rods were built and installed in 2019 and commissioned in the same year. Since then, the RFQ has been working very successfully. Recently it was opened for inspection and verification of its internal status. No damage and discoloration were observed. This contribution will describe the RFQ rebuild process, involving specific RF protections and other technical aspects related to the assembly of the structure. Results of the operation with a variety of beams will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOST022

About •

Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 11 July 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOST020

Visualisation of Pareto Optimal Spaces and Optimisation Solution Selection Using Parallel Coordinate Plots

cavity, impedance, GUI, ECR

2487

S.J. Smith, R. Apsimon, G. Burt, M.J.W. Southerby
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
S. Setiniyaz
Cockcroft Institute, Warrington, Cheshire, United Kingdom
S. Setiniyaz
Lancaster University, Lancaster, United Kingdom

In this paper, we build on previous work where multi-objective genetic algorithms were used to optimise RF cavities using non-uniform rational basis splines (NURBS) to improve the cavity geometries and reduce peak fields. These optimisations can produce thousands of Pareto optimal solutions, from which a final cavity solution must be selected based on design criteria, such as accelerating gradient and power requirements. As all points are considered equally optimal, this can prove difficult without further analysis. Here we focus on the visualisation of the Pareto optimal points and the final solution selection process. We have found that the use of clustering algorithms and parallel coordinate plots (PCPs) provide the best way to represent the data and perform the necessary trade-offs between the peak fields and shunt impedance required to pick a final design.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST020

About •

Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 29 June 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)